The principal on my mortgage is $123.45 this month and the remaining mortgage balance is $98,239.12. My house is 2000 square feet (288000 square inches).
My inchage this month is 123.45/98239.12*2000*144 = 361.91 square inches. This is
equivalent to a tile 19 in x 19 in located somewhere in
the bathroom behind the commode.